By employing Padé approximants to fit the lattice data of the ghost
propagator, it turns out that all the fit parameters of the
PAs are extremely large, of the order of \(\mathcal {O}(10^{10})\)  or
higher. This is caused by a pole very close to the origin, as can be
understood from Eq. (REF ).
We also verify that this feature persists when considering different
Padé approximants, indicating that this pole is indeed
physical. For the sake of exploring additional analytical structures of the
ghost propagator, we then impose this pole at the origin, through
the so-called partial Padé approximants
(PPAs) [1]}, [2]},
which, in this case, are expressed as
\(\mathbb {P}^M_N(p^2) = \frac{Q_M(p^2)}{R_N(p^2) \, p^2} \; ,\) 
